diff --git a/_includes/post.njk b/_includes/post.njk
index cfc157f..7520321 100644
--- a/_includes/post.njk
+++ b/_includes/post.njk
@@ -6,7 +6,7 @@ layout: base.njk
   <header class="post-header">
     <h1>{{ title }}</h1>
     <time datetime="{{ createdAt | dateFormat }}">{{ createdAt | dateFormat }}</time>
-    {% if updatedAt %}
+    {% if updatedAt and (updatedAt | isMoreThanHourAfter(createdAt)) %}
     <p class="updated-at">Updated: <time datetime="{{ updatedAt | dateFormat }}">{{ updatedAt | dateFormat }}</time></p>
     {% endif %}
   </header>
diff --git a/eleventy.config.js b/eleventy.config.js
index ccf1548..0d12675 100644
--- a/eleventy.config.js
+++ b/eleventy.config.js
@@ -4,6 +4,7 @@ const markdownItFootnote = require("markdown-it-footnote");
 const markdownItMermaid = require('markdown-it-mermaid').default
 const syntaxHighlight = require("@11ty/eleventy-plugin-syntaxhighlight");
 const fs = require("fs");
+const { DateTime } = require("luxon");
 
 const tagPattern = /(?<=^|\s)#([a-zA-Z][a-zA-Z0-9_]*)(?![a-zA-Z0-9_-])/g;
 
@@ -111,18 +112,30 @@ module.exports = (eleventyConfig) => {
   eleventyConfig.setLibrary("md", md);
 
   eleventyConfig.addFilter("dateFormat", (date) => {
-    const d = new Date(date);
-    return d.toLocaleDateString('en-US', {
-      year: 'numeric',
-      month: 'long',
-      day: 'numeric',
-      timeZone: 'UTC'
-    });
+    const dt = date instanceof Date 
+      ? DateTime.fromJSDate(date)
+      : DateTime.fromISO(date);
+    return dt.toFormat('MMMM d, yyyy');
   });
 
   eleventyConfig.addFilter("isoDate", (date) => {
-    const d = new Date(date);
-    return d.toISOString().split('T')[0];
+    const dt = date instanceof Date 
+      ? DateTime.fromJSDate(date)
+      : DateTime.fromISO(date);
+    return dt.toISODate();
+  });
+
+  eleventyConfig.addFilter("isMoreThanHourAfter", (date1, date2) => {
+    if (!date1 || !date2) return false;
+    const toDateTime = (d) => {
+      if (DateTime.isDateTime(d)) return d;
+      if (d instanceof Date) return DateTime.fromJSDate(d);
+      return DateTime.fromISO(d);
+    };
+    const dt1 = toDateTime(date1);
+    const dt2 = toDateTime(date2);
+    const diff = dt1.diff(dt2, 'hours').hours;
+    return Math.abs(diff) > 1;
   });
 
   eleventyConfig.addCollection("posts", (collectionApi) => {
diff --git a/package.json b/package.json
index e70f9f2..425d60c 100644
--- a/package.json
+++ b/package.json
@@ -14,6 +14,7 @@
   "dependencies": {
     "@11ty/eleventy": "^3.1.2",
     "@11ty/eleventy-plugin-syntaxhighlight": "^5.0.2",
+    "luxon": "^3.7.2",
     "markdown-it": "^14.1.0",
     "markdown-it-container": "^4.0.0",
     "markdown-it-footnote": "^4.0.0",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5a06652..fc839f4 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -14,6 +14,9 @@ importers:
       '@11ty/eleventy-plugin-syntaxhighlight':
         specifier: ^5.0.2
         version: 5.0.2
+      luxon:
+        specifier: ^3.7.2
+        version: 3.7.2
       markdown-it:
         specifier: ^14.1.0
         version: 14.1.0
diff --git a/posts/posts.11tydata.js b/posts/posts.11tydata.js
index c4a9da2..814dfdc 100644
--- a/posts/posts.11tydata.js
+++ b/posts/posts.11tydata.js
@@ -1,6 +1,7 @@
 const path = require("path");
 const fs = require("fs");
 const { execSync } = require("child_process");
+const { DateTime } = require("luxon");
 
 const getGitCreatedTime = (filePath) => {
   try {
@@ -9,7 +10,7 @@ const getGitCreatedTime = (filePath) => {
       { encoding: "utf-8", stdio: ["pipe", "pipe", "pipe"] }
     ).trim();
     if (result) {
-      return new Date(result);
+      return DateTime.fromISO(result);
     }
   } catch (e) {
     // Git command failed, return null
@@ -24,7 +25,7 @@ const getGitModifiedTime = (filePath) => {
       { encoding: "utf-8", stdio: ["pipe", "pipe", "pipe"] }
     ).trim();
     if (result) {
-      return new Date(result);
+      return DateTime.fromISO(result);
     }
   } catch (e) {
     // Git command failed, return null
@@ -43,7 +44,8 @@ const getTitleFromFilename = (filePath) => {
 const getFileCreatedTime = (filePath) => {
   try {
     const stats = fs.statSync(filePath);
-    return stats.birthtime || stats.mtime;
+    const time = stats.birthtime ?? stats.mtime;
+    return DateTime.fromJSDate(time);
   } catch (e) {
     return null;
   }
@@ -52,7 +54,7 @@ const getFileCreatedTime = (filePath) => {
 const getFileModifiedTime = (filePath) => {
   try {
     const stats = fs.statSync(filePath);
-    return stats.mtime;
+    return DateTime.fromJSDate(stats.mtime);
   } catch (e) {
     return null;
   }
@@ -60,9 +62,10 @@ const getFileModifiedTime = (filePath) => {
 
 const parseDate = (value) => {
   if (!value) return null;
-  if (value instanceof Date) return value;
-  const parsed = new Date(value);
-  return isNaN(parsed.getTime()) ? null : parsed;
+  if (DateTime.isDateTime(value)) return value;
+  if (value instanceof Date) return DateTime.fromJSDate(value);
+  const parsed = DateTime.fromISO(value);
+  return parsed.isValid ? parsed : null;
 }
 
 const getPostCreatedAt = (data) => {
@@ -79,7 +82,7 @@ const getPostCreatedAt = (data) => {
     return fileDate;
   }
 
-  return data.page.date;
+  return DateTime.fromJSDate(data.page.date);
 }
 
 module.exports = {
@@ -95,19 +98,9 @@ module.exports = {
     },
     createdAt: getPostCreatedAt,
     updatedAt: (data) => {
-      const modifiedDate = parseDate(data.updatedAt) ?? 
+      return parseDate(data.updatedAt) ?? 
         getGitModifiedTime(data.page.inputPath) ?? 
         getFileModifiedTime(data.page.inputPath);
-      const createdDate = getPostCreatedAt(data);
-
-      if (modifiedDate) {
-        // Only return updatedAt if it's AFTER created date (by more than a day)
-        const dayInMs = 24 * 60 * 60 * 1000;
-        if (modifiedDate > createdDate && (modifiedDate - createdDate) > dayInMs) {
-          return modifiedDate;
-        }
-      }
-      return createdDate;
     },
     permalink: (data) => {
       const title = data.title || getTitleFromFilename(data.page.inputPath);
@@ -115,7 +108,7 @@ module.exports = {
 
       const createdDate = getPostCreatedAt(data);
       
-      const isoDate = createdDate.toISOString().split('T')[0];
+      const isoDate = createdDate.toISODate();
       return `/post/${slug}/${isoDate}/`;
     }
   }